Preheat oven to 180ºC (356ºF). Line an 8-inch round baking pan with parchment paper, and set aside. NOTE: Alternatively, if you have a non-stick pan, liberally grease it with melted butter and dust it with a light layer of cocoa powder. This will leave your finished cake with smooth sides.
In a large mixing bowl, add sugar and eggs.
Using electric hand beaters, beat on low-medium speed for 30 seconds until well combined. Scrape down the sides with a rubber spatula.
With the beater running on medium speed, drizzle a little of the olive oil in at a time and beat for a few seconds, then drizzle in more oil, approx. 2 minutes in total. This emulsifies the oil into the batter.
Pour in the milk and vanilla. Beat for 20 seconds until well combined. Scrape down the sides.
Place a fine mesh sieve over the bowl and sift in flour, cocoa powder, baking powder and baking soda.
Sprinkle over the salt.
Beat on low-medium speed until incorporated, about 30 seconds, trying not over-mix, just until it’s incorporated into a smooth batter and no pockets or streaks of flour remain.
Scrape down the sides and gently fold through any remaining flour that was sitting on the sides of the bowl.
Pour batter into the prepared baking tin.
Bake for 40-45 minutes or until a toothpick inserted into the middle, comes out clean.
Remove from the oven and allow the cake to cool in the tin for 10 minutes.
Transfer to a wire rack to cool completely.